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PROCESS OF MANUFACTURING SULPHURIU ACID.

No. 325,262. Patented Sept. 1, 1885.

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J. McNAB.

PROCESS OF MANUFACTURING SULPHURIG ACID.

.. Patented Sept. 1, 1885.

UNITED STATES PATENT OFFICE.

JAMES MONAB, OF CAMDEN, NEYV JERSEY, ASSIGNOR- TO THE UNITED STATES CHEMICAL COMPANY, OF SAME PLACE.

PROCESS OF MANUFACTURING SULPHURI'C ACID.

SPECIFICATIQN forming part of Letters Patent No. 325,262, dated September 1, 1885.

Application filed May S, 1883. (No model.)

.To (025 whom it may concern:

Be it known that 1, JAMES McNaB, a resident of Camden, county of Camden, in the State of New Jersey, have invented a new and useful Improvement in the Manufacture of Sulphuric Acid, of which the following is a full, clear, and exact description of the same, reference being bad to the accompanying drawings, which form part of the specification.

My invention has reference to the process of manufacturing sulphuric acid therefor; but more particularly to a process to restore to the normal condition the contents of the chambers when they become what is technically known as sick or pale; and my ihvention con sists in the recovery of nitrous acid from the sulphuric acid obtained from the Gay-Lussac tower and passing it into the last chamber, where it is restored by a direct and auxiliary process, and all of which are fully set forth in the following specification and shown in the accompanying drawings.

Herctofore in manufacturing sulphuric acid the acidchambers would at intervals assume a sick or pale condition, due to the destruction or want of production of nitrous gas, indirectly caused by the requisite quantity of air and steam not being admitted with the sulphurous-acid gas, and when in this condition the sulphurous gas passes off into the atmosphere and is wasted. This destruction of the proper nitrous vapors occurs to the greatest extent in the last of the chambers, and it is here that the nitrous gas is mainly required. To remove this paleness or sickness, it has been customary to burn a large amount of nitrate of soda in the sulplnir-fnrnace, and thus introduce into the chambers the necessary quantity of nitrous vapor to oxidize the sulphurous acid and convert it into sulphuric acid; but this process, while it accomplishes the end desired, takes from twelve to fifteen hours to work the nitrous vapor around to thelast chamber, where it is required, before being able to restore the sick chamber to its normal condition. The object of my invention is to provide auxiliary means whereby nitrous vapor may be admitted in the requisite quantities to the last or any other chamber desired direct, and without first causing it to pass through the Glover tower and other chambers, thereby enabling a sick or pale chamber to be brought back to its normal condition in one hour, and, further, to produce the nitrous-acid gas by the sulphuric acid which passes from the Gay-Lussac tower, thereby obviating the necessity of consuming extra nitrate of soda. From this it is seen that I claim not only to remove the sickness from the acid-chambers in about onefifteenth the time heretofore required, but also to obtain this result without consuming any fresh nitrate of soda.

My improved tower may be used to great advantage in small works, where Glover and Gay-Lussac towers are seldom found.

In the drawings, Figure 1 is a plain view of a sulphuric-acid Works embodying my improvements; and Fig. 2 is a sectional elevation of portion of same, the parts being somewhat differently arranged to facilitate their explanation.

A A A A are the usual acid-chambers, and are connected together by fines B. C is the usual furnace in which thesulphur or iron pyrites is burned and the nitrate ofsoda boiled. The sulphurous gas, air, and nitric gas pass, by fine D, into the bottom of the Glover tower E, and then into the first chamber, A, by flue F. The gases from the last acid-chamber, A pass by flue G into the Gay-Lussac tower H, and thence into the air or chimney.

In the ordinary process sulphuric acid from the Glover tower is pumped up by air-pump J into flask or tank I, from which it is allowed to flow into the top of the GayLussac tower, absorbing the nitrous gas which may be passing up from chamber A". This acid, charged with the nitrous vapor, flows into the vessel J, from which it is raised by aiupressure into the tank K, and from which tank it flows slowly down through the Glover tower E, meeting the hot sulphurous gas, nitric gas, and air, which cause the said sulphuric acid to give up its nitrous acid, which latter joins the other gases and passes into the acid-chamber, where they meet with the requisite quantity of steam to convertthe sulphurous gas into hydrated sulphuric acid at the expense of the nitrous acid. The sulphuric acid which has passed through the Glo ver tower may run into a tank, E, or

may flow back into the vessel J, and be used in Gay-Lussac to absorb nitrous gas.

P is my auxiliary tower, and consists of a central flue, R, or cylinder of fire-clay or other material not acted upon by sulphuric acid, and rests in a terracotta basin, S, having an erturcs r for the passage of the sulphuric acid. This cylinder R is inclosed by a leaden cylinder, R, of larger diameter, and the intermediate or annular space filled in with sulphur, R. The top is closed in with a terracotta lid, V, made with a basin, V, having perforations a and upright flanged aperture V".

O is a terracotta pipe, which connects the aperture V with the last acid-chamber, A, the said pipe being inclined toward the said chamher to cause any condensations to run into said chamber. It may be provided with a damper, O, of any suitable construction, so that the tower P may be connected or disconnected with the chamber A as desired.

The joint between fine or pipe 0 and the acid-chamber consists of a terra-cotta section, W,inserted through thelead lining ofthe chamberand extending some distance within, so that any acid running down pipe 0 shall pass into the chamber without touching the lead joint. A lead flange, w, is bent up close to the pipesection W, and, if desired, cemented. Another flange may be raised or secured to the leaden chamber lining and encircling the pipe \V, as shown at w, and the annular trough this formed between the two flanges 'w w kept filled with water.

S is a spout to run off the sulphuric acid from basin S into the tank P.

M is a water-tank from which the requisite quantity may be siphoned or otherwise run off into the trough V by pipe on.

Sulphuric acid, saturated with nitrous acid, is siphoned or run off from tank K by pipe L into the trough V, where it mixes with the water, and then runs through aperture a into the tower and trickles down through the flint packing or filling P, where it meets with a jet of steam from pipe T, near the bottom, and provided with a valve, 15. The sulphuric acid gives up part of its nitrous vapors, allowing the nitrous gas to pass off by pipe 0 into the acidchamber A while the sulphuric acid passes down into tank P. This supplies the chamher with the requisite quantity of nitrous vapor in the proper condition to convert the sulphurous gas into sulphuric acid, this restoring the acid-chamber from its paleness or sickness to its-normal condition at once. Of course it is to be understood that the pipe 0 might connect With any other of th e acid-chambers, ortwo or more of them, and the construction of the apparatus might be modified in various ways without departing from my invention.

In this application I make no claim to the apparatus, as that forms subject-matter of an other application.

I claim 1. The herein-described process for restoring sick or pale acid-chambers, which consists in injecting nitrous vapors directly into said sick or pale chamber, the said nitrous vapors being separate and distinct from the gases or vapors incident to the manufacture of the acid.

2. The process for restoring sick or pale acidchambers in apparatus in which there are two or more acid-chambers, which consists in injecting nitrous vapors directly into the last of said chambers, or the one farthest from the sulphur-furnace, the admission of said nitrous vapors being separate and distinct from thegases or vapors incident to the manufacture of sulphuric acid.

3. The process for restoring sick or pale acidchambers, which consists in first freeing the nitrous vapors from sulphuric acid, holding them in solution by passing steam through said acid, and then injecting the nitrous vapors so produced into the pale or sick chamber.

FRANCIS T. CHAMBERS, JosHUA MATLAcK. 

